java.lang.AssertionError: Invalid start:-1
   at org.netbeans.modules.csl.api.OffsetRange.<init>(OffsetRange.java:65)
   at org.netbeans.modules.css.editor.csl.CssNodeElement.getOffsetRange(CssNodeElement.java:91)
   at org.netbeans.modules.csl.api.UiUtils$3.run(UiUtils.java:324)
   at org.netbeans.modules.csl.api.UiUtils$3.run(UiUtils.java:333)
   at org.netbeans.modules.csl.api.UiUtils$3.run(UiUtils.java:333)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:649)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:154)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:138)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:217)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:214)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:168)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:356)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:71)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:214)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:106)
   at org.netbeans.modules.csl.api.UiUtils$4.run(UiUtils.java:376)
   at org.netbeans.modules.progress.ui.RunOffEDTImpl$1.run(RunOffEDTImpl.java:160)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1973)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError: Invalid start:-1
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:425)
   at org.netbeans.modules.progress.ui.RunOffEDTImpl.runOffEventDispatchThreadImpl(RunOffEDTImpl.java:153)
   at org.netbeans.modules.progress.ui.RunOffEDTImpl.runOffEventDispatchThread(RunOffEDTImpl.java:115)
   at org.netbeans.api.progress.ProgressUtils.runOffEventDispatchThread(ProgressUtils.java:89)
   at org.netbeans.modules.csl.api.UiUtils.getElementLocation(UiUtils.java:371)
   at org.netbeans.modules.csl.api.UiUtils.open(UiUtils.java:115)
   at org.netbeans.modules.csl.navigation.actions.OpenAction.actionPerformed(OpenAction.java:92)
   at org.openide.explorer.view.TreeView$PopupSupport.mouseClicked(TreeView.java:1629)
   at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:253)
   at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252)
   at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252)
   at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252)
   at java.awt.Component.processMouseEvent(Component.java:6291)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6053)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4651)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4577)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4247)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
   at java.awt.Container.dispatchEventImpl(Container.java:2085)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:602)
   at java.awt.EventQueue$1.run(EventQueue.java:600)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:616)
   at java.awt.EventQueue$2.run(EventQueue.java:614)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:153)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)